The indolopyridoquinazoline alkaloid, 3-hydoxyrutaecarpine, was isolated from Leptothyrsa sprucei, along with 8-methoxypsoralen, 5-methoxypsoralen, imperatorin, imperatorin, kaempferol 3-O-alpha -L-rhamnopyranoside, clematine and cnidioside B. The usefulness of the gradient H-1=N-15 HMBC NMR spectroscopy in the structure elucidation of 3-hydroxyrutaecarpine is noted. (C) 2001 Elsevier Science Ltd. All rights reserved.